BZOJ1269: [AHOI2006]文本编辑器editor

  1 #include<iostream>
  2 #include<cstdio>
  3 #include<cstring>
  4 #include<queue>
  5 #include<algorithm>
  6 using namespace std;
  7 const int MAXN=2000000+10;
  8 const int BlockSize=3000 + 100,BlockNum=3000 + 10;
  9 int Cur=0,head,tot;
 10 char str[MAXN];
 11 struct Block
 12 {
 13     int size,nxt;
 14     bool rev;
 15     char a[BlockSize];
 16     void Clear()
 17     {
 18         size=0;nxt=-1,rev=0;
 19     }
 20 }B[BlockNum];
 21 queue<int>q;//鐢ㄤ竴涓槦鍒楁潵缁存姢褰撳墠鏈夊摢浜涘潡
 22 int NewNode()
 23 {
 24     int t=q.front();q.pop();
 25     B[t].Clear();
 26     return t;
 27 }
 28 inline void Pre()
 29 {
 30     while(q.size()!=0)    q.pop();
 31     for(int i=0;i<BlockNum;i++) q.push(i);
 32     head = NewNode();
 33 }
 34 void Find(int &idx,int &cur)
 35 {
 36     while(idx!=-1&&cur>B[idx].size) cur-=B[idx].size,idx=B[idx].nxt;
 37 }
 38 void Pushdown(int idx)
 39 {
 40     if(B[idx].rev) 
 41     {
 42     //    for(int i=0;i<B[idx].size;i++)
 43     //        cout<<B[idx].a[i];cout<<endl;
 44         reverse(B[idx].a,B[idx].a+B[idx].size);
 45     //    for(int i=0;i<B[idx].size;i++)
 46     //        cout<<B[idx].a[i];cout<<endl;
 47         B[idx].rev=0;
 48     }
 49         
 50 }
 51 inline void Split(int idx,int cur)
 52 {
 53     if(idx==-1||cur==B[idx].size)    return ;
 54     Pushdown(idx);
 55     int tot=NewNode();
 56     memcpy(B[tot].a,B[idx].a+cur,sizeof(char) * (B[idx].size-cur) );
 57     B[tot].size=B[idx].size-cur;
 58     B[idx].size=cur;
 59     B[tot].nxt=B[idx].nxt;
 60     B[idx].nxt=tot;
 61 }
 62 void Delet(int idx)
 63 {
 64     q.push(idx);
 65 }
 66 void Merge(int idx)
 67 {
 68     for(int i=idx;i!=-1;i=B[i].nxt)
 69         for(int j=B[i].nxt;j!=-1;j=B[j].nxt)
 70         {
 71             if(B[i].size+B[j].size<=BlockSize)
 72             {
 73                 Pushdown(i);
 74                 Pushdown(j);
 75                 memcpy(B[i].a+B[i].size,B[j].a,sizeof(char) * B[j].size);
 76                 B[i].size+=B[j].size;B[i].nxt=B[j].nxt;
 77                 Delet(j);
 78             }
 79             else break;
 80         }
 81 }
 82 inline void Insert(int cur,int x,char *str)
 83 {
 84     int idx=head;
 85     Find(idx,cur);
 86     Split(idx,cur);
 87     int i=0;//宸茬粡鍔犲叆鐨勪釜鏁?
 88     while(i<x)
 89     {
 90         int Limit=min(BlockSize,x-i);
 91         int tot=NewNode();
 92         memcpy(B[tot].a,str+i,sizeof(char) * Limit);
 93         B[tot].size=Limit;
 94         B[tot].nxt=B[idx].nxt;
 95         B[idx].nxt=tot;
 96         idx=B[idx].nxt;
 97         i+=Limit;
 98     }
 99     Merge(head);
100 }
101 void Print(int cur)
102 {
103     int idx=head;
104     Find(idx,cur);
105     if(cur==B[idx].size) idx=B[idx].nxt,cur=0;
106     Pushdown(idx);
107     printf("%c\n",B[idx].a[cur]);
108 }
109 void Rever(int l,int r)
110 {
111     int idx=head;
112     Find(idx,l);
113     Split(idx,l);
114     int Start=idx,StartNxt=B[idx].nxt;
115     idx=head;
116     Find(idx,r);
117     Split(idx,r);
118     int EndNxt=B[idx].nxt;
119     int Tmp[BlockNum],cnt=0;
120     for(int i=StartNxt;i!=EndNxt;i=B[i].nxt)
121         B[i].rev^=1,Tmp[++cnt]=i;
122     Tmp[++cnt]=Start;Tmp[0]=EndNxt;
123     for(int i=cnt;i>=1;i--)
124         B[Tmp[i]].nxt=Tmp[i-1];
125     Merge(head);
126 }
127 void Dele(int l,int r)
128 {
129     int idx=head;
130     Find(idx,l);
131     Split(idx,l);
132     int Start=idx,StartNxt=B[idx].nxt;
133     idx=head;
134     Find(idx,r);
135     Split(idx,r);
136     int EndNxt=B[idx].nxt;
137     for(int i=StartNxt;i!=EndNxt;i=B[i].nxt)    Delet(i);
138     B[Start].nxt=EndNxt;
139     Merge(head);
140 }
141 int main()  
142 {
143     #ifdef WIN32
144     freopen("a.in","r",stdin);
145     #else
146     #endif
147     int N;scanf("%d",&N);
148     char opt[20];
149     Pre();
150     while(N--)
151     {
152         scanf("%s",opt);
153         if(opt[0]=='M') 
154             scanf("%d",&Cur);
155         else if(opt[0]=='I')
156         {
157             int len;
158             scanf("%d", &len);
159             int i = 0;
160             while(i < len) {char ch = getchar();if(ch >= 32 && ch <= 126) str[i++] = ch;}
161             str[i++] = '\0';
162             Insert(Cur,len,str);
163         }
164         else if(opt[0]=='D')
165         {
166             int x;
167             scanf("%d",&x);
168             Dele(Cur,Cur+x);
169         }
170         else if(opt[0]=='R')
171         {
172             int x;
173             scanf("%d",&x);
174             Rever(Cur,x+Cur);
175         }
176         else if(opt[0]=='G')    
177             Print(Cur);
178         else if(opt[0]=='P')    Cur--;
179         else if(opt[0]=='N')    Cur++;
180     }
181     return 0;
182 }